toyota 10.5'' differential

I want to get out of some didactic doubts, I don't know how many generations there are or is it the same but the drought and tundra some come with a 10.5 differential this is hard but not as resistant at the ends, maximum 2000 pounds and some series 70 come with a 9.5 floating differential but they resist according to the Toyota 2900 pounds, my personal opinion they resist without forcing it between 2900 and 3100, how many pounds could a 10.5 '' move by modifying its ends and some other improvement? What size is the Toyota Coaster annular gear? I searched and searched, I found its tooth pitch only, no sizes and through other research I found that its maximum weight would be 4000 pounds, it is floating. The Dana 70s are 10.5 and easily move at least double that, 8,000 pounds. My idea for a Toyota Coaster differential would be to compare it in size to a Dana 70, but according to Toyota, it would only be 4,000 pounds, and I'm missing another 4,000.
? So, should the ring gear be smaller, or not? A 10.5 Tundra with floating axles should easily move 10,000 pounds, obviously with a good engine that can move that weight. What I'm trying to get at with this is that I'm doing a study on the maximum weights supported without the material suffering too much and its cost being feasible, and I'm interested in Toyota mechanics.

 

Not entirely following everything you said. But the Toyota 10.5 AXLE is semi float, most certainly the limiting factor in what the axle can handle. This is why even though the diff is the same size or larger than many higher rated vehicles, the axle is not rated as high. If you're not aware (and if you are skip this part) a semi float axle has the axle shaft taking all the shear load (weight of the vehicle) as well as transmitting torque to the tire. A full float axle, which is what a Dana 60,70,80, and many others have, has a duplex bearing pair at the hub so the hub entirely reacts the shear and bending moment from the tire and weight of the vehicle. The axle shaft is "floating" meaning it's only transmitting torque to the hub and does not see any other loads. Because the Toyota axle is semi float, the axle shaft is multi-tasking and reacting all loads and is why the axle is rated at less capability.

The DIFFERENTIAL however is a totally different story. I'm not sure of the specifics besides it's a 36 spline output so pretty good sized. The differential (3rd member) could be swapped into something else, like a custom housing, which is full float. That would be the strongest option and best of multiple worlds: you get a large differential, large output splines, a removable 3rd member, full float, etc. and many dedicated offroad vehicles do this. You can buy a housing from Front Range Off-road (called a Diamond Axle) that is custom built to what you want and will use a Toyota 10.5 differential.

The Land Cruiser axles sometimes are or are not full float, depending on the model and year. For example a 91-94 80 series is semi float, but 95-97 is full float and because of that is much more desirable and capable even though it's the same 9.5" differential. Not sure if that answers any of your questions...

 

Now can we make that fabbed axle etc work with the abs/tone ring to maintain functional 4wheel drive lol

 

I seem to recall Front Range Off-road offering a full floater conversion kit. They have offerings for some of the smaller Toyota axles but didn’t/don’t show the 10.5 even when they offered it. I emailed them a couple of years ago about it; I think they retain everything. Might have to fire off another email. If they offer the kit or are willing to make a production run, I smell a group buy..

 

I emailed them awhile back never heard back. I’m sure spidertrax could make something

 

They have this one without hubs it sounds like.

https://frontrangeoffroadfab.com/10-5-diamond-axle-housing-builder-style/

 

91-92 were semi float, 93-97 were full float for the 80 series

 

According to a Hino employee (they manufacture the axle), the actual design GAWR for the 10.5” axle is about 5500 lbs. For anyone that has disassembled one of these, it’s fairly easy to surmise, based on component size, that the supplied number is well within the realm of what it can carry.

Coasters have a similar 10.5” differential (same diff to housing gasket), but the axle spline count is different. Coasters with the 10.5” are rated for a max gross vehicle weight of over 12000lbs. They have very heavy FF housings and big hubs.